I am new to OnePlus, new to Android, new to smartphones, so I apologize for my ignorance if that is the cause of my problem. When I make a phone call and need to input numbers to respond to questions or a menu, I can press the numbers on the keypad and they show up on my phone . . . but they send no tones and so, of course, no signals are received at the other end. I have just updated to the latest lollipop software. Can anyone help me?